Raising clams at home is a form of aquaculture, which is the farming of aquatic organisms such as fish, crustaceans, and mollusks. There are many types of clams, but the exact number depends on how they are classified. Some estimates put the number of different species of clams at around 300-400.
More and more people are starting to understand the benefits of raising clams, and beyond the obvious reason of adding to the sustainability of your own household’s food supply, there are a number of other compelling reasons to culture and grow your own clams.
By raising your own clams, you’ll assure that you’re getting the best quality if you control as many factors as you can. The clams will always offer a fresher product than purchasing them anywhere else, and you can even grow them for profit if they are well-managed.
Other advantages of raising clams include water cleaning/filtration provided by the clams and the fact that (unlike all other forms of aquaculture) clams require no food supply provided by the farmer.
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Methods of Growing Clams
The topic of how to raise clams using which methods can be very in-depth and extensive, but to simplify as much as possible, there are basically 4 methods of growing clams. The methods are Wild Harvesting, Aquaculture, Bags or cages, and the Benthic Method.
Wild harvest: This is the traditional method of collecting clams from natural beds in the wild. This method is sustainable if the population is managed properly but can be limited by the availability of clams in the wild.
The process of wild harvest typically begins with identifying a healthy population of clam beds. This location is typically characterized by sandy or muddy bottoms and relatively low wave action. The clammers use rakes or dredges to collect the clams from the ocean floor.
Rakes are typically used to collect clams from the surface of the ocean floor, while dredges are used to collect clams from deeper areas.
Wild harvest is considered a sustainable method of harvesting clams if the population is managed properly. The problem is, the availability of clams in the wild can be limited, and over-harvesting can lead to a decline in the population.
Additionally, wild harvest can also be subject to natural events such as storms, high waves, and pollution, which can affect the availability and quality of the clams.
Aquaculture: This is the method of farming clams in controlled conditions, such as in tanks, ponds or in the ocean. Clams are typically grown in culture systems where they are suspended in the water column and provided with food, oxygen, and other necessary conditions to grow.
The process of aquaculture starts with the selection of a suitable species of clam for cultivation. Remember, there are a lot of species of clams! The choice of clam can vary depending on the location, water conditions, and market demand.
Next, the clams are obtained, either through hatcheries or by collecting them from wild populations. The clams are then placed in tanks or ponds that are specifically designed for the cultivation of clams.
The water in the tanks or ponds is carefully controlled to provide the best conditions for the clams to grow. This includes maintaining the right temperature, salt content, and pH levels, as well as providing sufficient oxygen and food for the clams. The clams are typically fed a diet of phytoplankton, which is their natural food source.
The clams are then left to grow until they reach a suitable size for harvest. This can take anywhere from several months to a few years, depending on the species of clam and the growing conditions.
Aquaculture is considered a sustainable method of growing clams because it allows for the cultivation of clams in areas where wild harvest is not possible or sustainable.
Additionally, it also allows for the cultivation of clams in a controlled environment, which can lead to a higher survival rate and a more consistent supply of clams.
However, aquaculture can also be subject to disease and parasites, which can negatively impact the growth and survival of the clams.
Overall, clam aquaculture is a complex process that requires knowledge of the biology, physiology and technology of the clam species to be grown, as well as knowledge of water chemistry, water flow, and other environmental parameters.
If clams are grown in the ocean, many controllable and variable factors related to aquaculture will not have to be directly addressed.
Bags or cages method: This method consists of growing clams in net bags or cages that are suspended in the water column, this method is similar to aquaculture but the clams are not in contact with the sediment.
Young clams (about 4 mm minimum) are placed in bags or cages that are specifically designed for the cultivation of clams.
The bags or cages are suspended in the water column, and it’s typically in a location that provides the optimal water conditions for the clams to grow. The clams can feed continuously (on phytoplankton) while submerged and protected in the bags or cages.
But, the suspended bags or cages method can be subject to natural events like storms, high waves, and pollution. This can affect the survival and growth of the clams. It is important to monitor the clams and the water conditions to ensure the survival and growth of the clams.
Floating cages method: This method involves cages full of clams that float at surface level. This method promotes faster growth, provides a bit more dissolved oxygen, and keeps the clams away from many bottom-dwelling predators like crabs, otters, and even starfish which cannot easily access suspended clams.
The use of floating cages to raise clams has several advantages over traditional aquaculture methods such as benthic or suspended bags method. The floating cages can be moved to different locations to take advantage of seasonal changes in water conditions, and can also be moved to protect the clams from storms or other adverse conditions.
In addition, floating cages can also be used in deeper waters, where benthic or suspended bags methods are not practical or even possible.
However, floating cages are also subject to the same challenges as other aquaculture methods, such as disease and parasites, which can negatively impact the growth and survival of the clams.
Also, floating cages are more expensive to build and maintain than other aquaculture methods. While they are certainly easier to access and manage than any other method, they are vulnerable to damage by wave action in rough waters.
Benthic Method: This method of clam farming involves the cultivation of clams on the ocean floor and is similar to wild harvest but the clams are grown in a controlled environment.
The process begins with selecting a suitable location for the clam beds, typically in areas with a sandy or muddy bottom and relatively low wave action. The area is prepared by removing any debris, and the bottom is smoothed to create a suitable substrate for the clams.
Next, the clams are introduced to the area, typically as juvenile or “seed” clams. These clams can be obtained from hatcheries or from wild populations. The clams are placed on the ocean floor in close proximity to one another and are then left to grow, but they are not fed. The clams filter the water and extract the plankton, which is their natural food.
The benthic method of growing clams is considered a sustainable method, because the clams are grown in a natural environment and do not require the use of additional feed or chemicals. This method also allows growth in areas where wild harvest is not possible or is not sustainable, and it can also increase the population of clams in an area, which can help to maintain the balance of the aquatic ecosystem.
However, the benthic method can also be subject to natural events such as storms, high waves, and pollution, and that can affect the survival and growth of the clams. It is important to monitor the clams and the water conditions to ensure the survival and growth of the clams.
This method leaves the clams as vulnerable as they would be in the wild.
Each method has its pros and cons, but after researching extensively, it seems like a floating or suspended cage or bag is a bit easier since it is not affected much by tidal movements and it allows the oysters to remain close to the surface where they’ll have the most dissolved oxygen.
What Are the Main Differences Between Oysters and Clams?
Clams and Oysters differ in many ways including their habitat, reproductive process, and appearance. Unlike oysters which like to cling to rocks and make their own reefs in the wild, clams prefer to bury themselves in the sand and remain covered most of the time. Because of this, the exfoliating action of the sand on the clam’s shell makes it smoother and thinner than the tough and jagged oyster shell.
Appearance: Clams typically have a round or oval shape, while oysters have a flatter, elongated shape. Clams also tend to be smaller than oysters, and they have two equal-sized shells, while oysters have a large, flat bottom shell and a smaller, curved top shell.
Habitat: Clams are usually found in sandy or muddy bottoms, while oysters are typically found on rocks or other hard surfaces.
Feeding: Clams are filter feeders and use their gills to filter water and extract food particles, while oysters are filter and deposit feeders, they filter water to extract food particles and also feed on the organic matter that falls on the bottom.
Reproduction: Clams are typically hermaphrodites and can change their sex during their lifetime, while oysters are typically monoecious, meaning that they have both male and female reproductive organs.
Harvesting: Clams are typically harvested using rakes or dredges, while oysters are typically harvested by hand or by using tongs.
Culinary use: Clams and oysters are both consumed as seafood and are a popular delicacy, but they are typically prepared differently and have slightly different flavors. Clams are usually steamed, fried or used in a variety of dishes such as chowder, pasta, and sushi, while oysters are usually served raw, on the half shell, or grilled.
Economic value: Clams and oysters are both valuable resources, but oysters are considered a more sought after species in terms of commercial value, they are more expensive, and have a wider variety of culinary use.
Can I Raise Clams at Home?
One can certainly raise clams in a backyard aquaculture environment, with a relatively low start-up cost and few barriers to entry. However, growing clams outside of the ocean does require meticulous monitoring of water conditions and attention to detail, along with some very specific knowledge and training.
While clams can be raised in a freshwater pond, for example, they tend to clean the water of all algae which can make the water look nice and clear, but it will make the water too nutrient-poor to support much (if any) other life like fish and plankton.
Here are some basic steps you’ll need to take in order to create your own backyard clam farm, and we’ll expand on the details later in this article.
- Choose a suitable species: Different species of clams have different requirements, so it is important to research and choose a species that is suitable for your pond or tank conditions. Squamosa clams are reputed to be one of the easiest species to grow and maintain.
- Create a suitable environment: Clams require a substrate of sand or gravel and a source of light. They also need appropriate water conditions, such as a salinity level between 1.020 and 1.025, and pH between 7.5-8.5.
- Obtain clam seeds or spat: You can obtain clam seeds or spat from a hatchery or a supplier, or collect them from the wild.
- Plant clam seeds or spat: Plant the clam seeds or spat in the substrate.
- Feed the clams: Clams need to be fed a diet of phytoplankton or other small aquatic organisms.
- Monitor water quality: Regularly check and monitor water quality, including nitrate and phosphate levels, and perform regular water changes as needed.
- Harvest the clams: Once the clams have reached a suitable size, you can harvest them. A good size to harvest is around 3″ – 5″ which can be obtained after growing for 2-4 years.
Keep in mind that clam cultivation is a long-term process and clam growth is slow, so it’s important to be patient and persistent.
PRO TIP If at all possible, it’s best to grow clams in their natural environment, and several states offer help for those getting started with shellfish farming. You can obtain licenses/permission to grow your clams in the ocean even if you don’t have access to the water from your home. This type of farming is far different than using your own water in a tank or pond on your inland property.
PRO TIP #2 For very small-scale clam farming or keeping clams in an aquarium, here’s a very helpful, illustrated step-by-step guide to start your own clam farm.
What Tools, Supplies and Equipment do I Need to Start Clam Farming in a Pond?
For growing clams in a pond or large tank, it will be necessary to have a number of important supplies and equipment. Some important items would be a water testing kit, aeration system, lighting, food, harvesting equipment and protective clothing.
Here’s a brief outline of what you’ll need:
- A suitable area: You will need a pond or tank that is large enough to accommodate the number of clams you plan to raise. The pond or tank should be located in a shaded area, and should have a substrate of sand or gravel.
- Water testing kit: You will need a water testing kit to monitor water quality, including pH, salinity, and nitrate and phosphate levels.
- Aeration system: Clams need a steady supply of oxygen to survive, so you will need an aeration system to keep the water oxygenated.
- Lighting: Some species of clams require a source of light, so you will need to provide appropriate lighting for the species you are raising.
- Feed: Clams need to be fed a diet of phytoplankton or other small aquatic organisms. You can purchase this type of feed from a supplier, or culture it yourself.
- Harvesting equipment: You will need equipment to harvest the clams, such as a rake or dredge.
- Protective clothing: When handling clams, you should wear gloves and boots to protect yourself from cuts and punctures.
- Clam seeds or spat: You will need to obtain clam seeds or spat to start your clam farm. This can be obtained from a hatchery, or collected from the wild.
- Monitoring equipment: You may need some monitoring equipment like a thermometer, dissolved oxygen, pH, salinity, and turbidity meter to keep track of the environmental conditions for the clams.
Do Clams Need to Stay Submerged or Can They Live Out of Water for a Time?
Clams are aquatic animals that require a consistent water supply in order to survive. They are bivalve mollusks, which means they have two shells that protect their soft body and gills. Clams filter water through their gills to extract oxygen and food, and they also use their gills to excrete waste. As long as a clam shell is not damaged, it can survive for days out of water, if the shell is at least kept moist, it can survive for as long as 2 weeks outside of water.
However, depending on the species, some oysters have the ability to close their shells and survive for short periods of time out of water, in a moist and shaded environment. But this is not a sustainable way of living for them. They will eventually die if they are not returned to an aquatic environment.
Clams can’t breathe in an air environment. When there is a drought, however, some clams can spend months, even years, out of water. They do this by closing up and shutting down all processes except for the essential ones, and they carry these out without oxygen. The clam opens up slightly to get rid of any waste that builds up, but it only does this once in a while to avoid losing too much moisture.
Eco-Spark Canada
According to Canadian environmental charity Eco-Spark, clams have been known to live out of water for years, though my better judgment tells me they would die from lack of food and oxygen since they can’t eat or breathe out of water.
I’m not a scientist so I can’t really say for sure!
Can I Raise Clams in an Aquarium?
It is possible to raise clams in an aquarium. However, it is important to note that clams are filter feeders. Because of this, they require a steady supply of phytoplankton or other microorganisms on which to feed. That means the aquarium would need to be set up with equipment and conditions that can support the growth of these organisms, such as a protein skimmer, strong lighting, and proper water flow.
To grow clams in an aquarium, you will need to provide them with a suitable environment that mimics their natural habitat. This includes a substrate of sand or gravel, a source of light, and appropriate water conditions, such as a salinity level between 1.020 and 1.025.
The suggested bottom material of your tank would be 4-6 inches of mostly sand, mixed with some fine gravel.
You will also need to maintain good water quality by performing regular water changes and monitoring levels of nitrates and phosphates. What’s more, you will need to feed the clams a diet of phytoplankton or other small aquatic organisms.
It’s crucial that the aquarium be large enough to accommodate the clams as they grow.
By adding other creatures like fish and crabs, you’ll help the clam. Other organisms create waste that clams (apparently) love to eat. You can supplement a clam’s diet with sinking algae wafers available at pet stores.
Generally, a 10 to 30-gallon aquarium can handle 1 or 2 healthy adult oysters, assuming there are other fish and crabs, etc. in your tank.
PRO TIP Clams grown in a freshwater aquarium can certainly thrive and grow, but because they’ll need so much attention and space, it may not be the best place to grow clams for food.
PRO TIP #2 A dead clam releases ammonia which can have a devastating effect on other creatures living in your tank. It’s tough to find clams most of the time since they bury themselves, so finding a dead one can be a real challenge. Clams will usually respond to a touch of a finger by moving or closing, so if there is no response over time, you may be able to assume a clam is dead.
What Do Clams Eat?
Clams are filter feeders, which means they filter small particles, such as phytoplankton, out of the water for food. In their natural habitat, oysters feed on a variety of microorganisms, including algae, diatoms, and zooplankton.
If you’re considering raising your own clams, this is good news. You’ll never need to buy clam feed unless you are growing clams in an aquarium.
In aquaculture, clams typically feed on a diet of microalgae, such as phytoplankton, that is rich in protein and essential fatty acids. This microalgae diet is most often available naturally in the ocean environment but may be cultured if you’re raising clams in a closed aquaculture system.
It is important to note that clams, like all bivalves, also filter water for suspended particles, sediment, and nutrients and keep their habitat clean and healthy.
Clams can help improve water quality by removing suspended particles and excess nutrients, which can reduce the growth of harmful microorganisms and improve overall water clarity.
Water Quality and Temperature for Clams
Clams prefer cold, clean, and well-oxygenated water. The ideal temperature range for most clams is between 35-55°F (1.7-12.8°C). They also require a certain level of salinity, typically between 20-30 parts per thousand (ppt). Clams also require a clean environment, free of pollution and excessive sediment.
Water temperature: Clams prefer cold water, with an ideal temperature range between 35-55°F (1.7-12.8°C). They can tolerate slightly warmer temperatures, but prolonged exposure to temperatures above 60°F (15.6°C) can lead to stress and death.
Salinity: Clams require a certain level of salinity, typically between 20-30 parts per thousand (ppt). They can tolerate a range of salinities, but optimal growth occurs at a salinity of around 25 ppt.
Water quality: Clams require clean and well-oxygenated water to survive. They are sensitive to pollution and excessive sediment, and water with high levels of pollutants can lead to stress and death.
Dissolved oxygen: Clams require a certain level of dissolved oxygen in the water. The optimal dissolved oxygen level is between 5-9 mg/L, and they may not survive in water with dissolved oxygen levels below 3 mg/L.
pH: Clams require a neutral pH level of 7.0, and they may not survive in water with a pH level above 8.5 or below 6.5.
Light: Clams require minimal light, and exposure to direct sunlight or bright light can cause stress and death.
Nutrients: Clams require a certain level of nutrients in the water, including nitrates, phosphates, and other trace elements. They also require a source of food, such as phytoplankton, to survive.
Do Clams Pollute or Clean the Water?
Clams are filter feeders and they can help to clean the water by removing particles such as phytoplankton, algae, and other small organisms. They feed by filtering water through their gills, which trap food particles. As a result, the water that passes through a clam bed can be cleaner than the water in the surrounding area.
As mentioned earlier, clams are filter feeders, which means they filter water through their gills to capture and consume food particles.
They also remove various pollutants and suspended particles, such as algae, bacteria, sediment, and heavy metals. This helps to improve water clarity and reduce the levels of pollutants in the water.
Clams also help to remove excess nitrogen from the water. Nitrogen is a key nutrient for plant and algae growth, but excessive levels can lead to eutrophication (excessive growth of aquatic plants and algae) and oxygen depletion.
Clams can remove nitrogen from the water through their excretion and decomposition of organic matter.
Clams also act as biological filters, helping to remove pollutants by breaking down organic matter and converting it into nutrients that can be used by other organisms.
Clams are considered an important part of the ecosystem. They help to maintain the balance of the aquatic food web. Clams are also considered an important indicator species, the presence or absence of clams can indicate the health of an ecosystem.
An oyster and clam opening tool like this can make your entire clam-raising experience easier – especially once you get to the very end – the kitchen table!
How Long Does it Take to Farm Clams?
The time it takes to raise a clam can vary depending on a few factors, such as the species of clam, the growing conditions, and the size of the spat (baby clams) at the start of the cultivation process, but for most clam species, it can take 2 – 5 years to grow to a marketable size.
Oysters, on the other hand, can be ready for market in 6 – 18 months and can grow up to 20 centimeters (8 inches) wide.
This time frame can be shortened or lengthened depending on the species, some species of clam are faster growing while others are slower.
For example, the Pacific razor clam, a species that is commonly harvested for food, can take between 2-3 years to reach a marketable size.
The Eastern softshell clam usually takes about 3-4 years to reach maturity and a marketable size, and the Hard clam can take from 2-5 years to reach maturity and a marketable size.
Other factors that can affect the growth rate of clams include water temperature, salinity, water quality, and the availability of food. Clams that are raised in ideal conditions and with proper management can grow faster and reach a marketable size more quickly.
It’s worth noting that the size considered as “marketable size” can also vary depending on the species, the region and the market.
Will Clams Reproduce?
Clams can reproduce in an aquaculture pond under the right conditions. The success of reproducing clams in an aquaculture pond depends on several factors, including water temperature, salinity, water quality, and the availability of food. These are the same factors that determine success in all other aspects of clam raising like growing time, maximum size, overall health, etc.
Aquaculture ponds are typically managed to provide ideal conditions for the clams, such as maintaining the right water temperature, salinity, and water quality, and providing a food source.
However, some clams might not reproduce in the aquaculture pond, as the conditions in the pond may not be suitable for reproduction. Some species can reproduce asexually and others are hermaphrodites, so they can reproduce without the need for a partner.
Reproduction in aquaculture ponds can also be enhanced by using selective breeding and by manipulating environmental factors such as water temperature, salinity, and light.
How Do Clams Reproduce?
Clams are typically dioecious, meaning they have separate sexes and produce both eggs and sperm. During spawning, clams release their eggs and sperm into the water column. The eggs and sperm then combine to form a free-swimming larva called a veliger. The veliger then settles and undergoes metamorphosis to form a juvenile clam.
This process can take place during certain times of the year, which depends on the species, and water conditions.
Some species of clams also reproduce asexually, through a process called fragmentation or by producing small clonal individuals called spat. This process is called bivalve reproduction, it’s a way of reproducing without the need for fertilization.
In addition, human activities such as pollution, overfishing, and habitat destruction can also have an impact on the reproduction of clams.
Because the process of reproduction is a bit random in the wild, it’s best to rely on a steady source of reliable spat. New, young clams are relatively easy to source and quite inexpensive.
Where Can I Get Young Clams to Grow?
Fortunately, there are a number of shellfish hatcheries or specialized producers that can provide you with spat (baby clams) to begin the growing process. This is the recommended method of growing clams rather than working through the clam spawning process.
It’s possible to allow clams to reproduce naturally, but it’s not the best method because of the unreliable nature of spawning variables like environmental conditions, weather, water quality and suitability issues, and more.
Key Takeaways – Raising Your Own Clams
Raising clams for your homestead will probably be more challenging than raising fish in an aquaculture environment unless you have easy and direct access to salinated water (like a home with a property that borders an ocean or brackish creek, etc.)
Raising clams in a very well-managed pond or an aquarium are your only other choices, but since it takes up to 5 years for clams to reach an eating size, an aquarium can be a time-consuming and expensive way to get a small amount of clam meat.
If you live near the ocean (but not on it), you can contact your local fisheries authority to find out what programs are available to help you access an appropriate area and other needed resources for your small-scale clam farm.
References:
- https://projects.sare.org/wp-content/uploads/960820presentation-7.pdf
- https://pethelpful.com/fish-aquariums/Introduction-Keeping-Clams-In-Aquariums
- https://www.wikihow.com/Take-Care-of-a-Live-Clam
- https://www.ecospark.ca/clam